__getattribute__ hook and len() problem

[ernest]

Hi!

I have this class that overrides the __getattribute__ method,
so that it returns the attributes of str(self) instead of the
attributes of self.

class Part(object):
    def __init__(self):
        self.content = []
    def __str__(self):
        return str.join('\n', self.content)
    def __getattribute__(self, name):
        if name in ['content', 'write', '__str__']:
            return object.__getattribute__(self, name)
        else:
            return str(self).__getattribute__(name)
    def write(self, data):
        self.content.append(data)

Then I do:

In [50]: p = Part()

In [51]: p.write('foo')

In [52]: p.upper()
Out[56]: 'FOO'

This is okay, works as expected.

However, len(p) fails:

TypeError: object of type 'Part' has no len()

And yet, p.__len__() returns 3. I though len(object) simply
called object.__len__.

Can somebody shed some light on this??

Many thanks in advance.

Ernest